Flooded rivers have a high water volume. The force of flood water is enough to pick up and carry silt, sand, gravel, and metal ore such as gold. The aggregate material is carried downstream in suspension Heavy particles such as gold bearing rock settles wherever the water slows enough to allow it to drop out of suspension. Rivers flow through channels with irregularities, rock outcropping, bends, narrow spots, wide spots, intrusions of bedrock, which causes the water to flow at different speeds along the path. Material drops out of suspension when the flow is slowed along the stream.
Various methods are employed for physically separating aggregates such as panning, rocker boxes, sluices, and hydraulic mining. All were successful but some more than others. Hydraulic mining, that is, using a powerful stream of water coming from a large, high pressure and flow hose to wash mounds or literally, hills, of dirt away from gold deposits, was very destructive of the environment. Panning, placing a small amount of dirt or aggregate into a small shallow pan and rinsing the dirt away from the gold, is quite slow and cumbersome. A rocker box was usually made from a wooden box with rockers on the bottom and a upward extending handle used to rock the box to and fro, generally included a classifier sieve or screen at the top and was lined with riffles and usually a carpet on the bottom to help catch gold particles as water washed over dirt or an aggregate sample. Modern devices often use electric or air operated equipment to shake or vibrate the sluice or classifier.
A conventional sluice comprises a trough supported at a declining angle including water flowing over a series of irregular shaped rails, ridges, or ripples whereby the aggregate is poured into the inlet of the sluice and the flow of water through the sluice provided all the energy for removing the dirt form the gold, as the water flowed over the dirt or aggregate sample placed in the sluice. Sluice boxes work by creating a straight channel with regularly spaced apart slow areas created by riffles, ridges, or other irregularities in the bottom surface. Each riffle creates an eddy consisting of a backflow of water that allows the heavier particles to settle out. Aggregate material is placed at the top of the box and carried in suspension down the channel by a flow of water. The heavier metal or minerals drop out of suspension as the water slows on the back side of the riffles. Too much water carries the gold higher in suspension because the upper layer of water is not affected by the riffles as much as the lower layer of water. The lower layer of water rolls behind the riffle whereby the upper layer of water flows over the eddy. The eddy can slow the upper layer but it is not as effective as the riffles. If the flow of water is too slow, the gold to drop out too quickly allowing lighter material to drop out and fill the space between the riffles which eliminates the slow spots allowing the gold to flow out of the sluice with the waste aggregate.
As a general rule a 1″ drop is used per foot of length of your box. An acceptable flow rate allows the gold to drop out of suspension and the lighter material to flow out of the box.
Because semi-precious stones and/or minerals and/or gems are typically the same weight or lighter than the aggregate waste material, a sluice does not provide the requisite separation and concentration. Therefore, mineral or gem containing aggregate ore is typically separated using sieves or screens of a selected size and shape. Water is helpful in dissolving the silt and dirt particles carrying away the mud and washing the product gems making them reflect more light and becoming more visible to the eye of the prospector.
Individuals pan for gold and visit mining sites to look for gold, silver, precious and semi precious gems as a hobby. In order to introduce an inexperience person to the method of mining using simple separation devices, activities are often arranged by mining or rock businesses so that visitors can pan gold, minerals or gems from ore containing rock, dirt, sand, and other aggregate materials to separate any valuable products therefrom. Often a participant will purchase a bucket of aggregate ore in quantities of 1 gal or 5 gallons, and use a pan or sluice provided by the business to process the aggregate ore and experience the separation and concentration of the products. To make the experience more interesting, some businesses will premix a specific amount by weight or percent of valuable products in the aggregate ore in order to guarantee the customer will have a rewarding experience.
The present invention incorporates a classifier, concentrator, and separator sluice apparatus contained within a compact unit such as a barrel or drum using recirculated water in order that the self contained unit can be utilized inside of a building in a designated area enabling use in bad weather.